Steering repeater compass



June.14, 19.38. F HODGMAN 2,120,951

STEERING REPEATER COMPASS original Filed April 15,4 1935 2 sheets-sheet 1 9 59 l I IVENTOR fkgYDEH/c/f MMG/mm l June 14, 1938..

F. s. HoDGMAN 2,120,951 STEERING REPEATER cMPAss original Filed April 13, 1935 2 Sheets-Sheet 2 Patented June 14, 1938 Divided and this application Decemlier 3l, 1936, Serial No. 118,495. In Japan April 8 Claims.

This invention relates to repeater compas-ses such as now used for the steering of ships in connection with a master compass, such as a gyrascopic compass.

The gyroscopic compass has now become an instrumentof great precision, so that changes of course of a minute in azimuth or less may be detected. It is, however, diilcult for the helmsman to see such a small change on an ordinary 10 repeater card and several types of multiple dials have been proposed, including an auxiliary or fine card driven at 36 to 1 ratio. Such a card, however,- is diilcult for the average helmsman to follow.

- According to my invention, I propose to retain y the advantages of the single 360 card which rotates once for a complete turn of the ship, but Ato show thereon in readable or magnified form a. very small change in the heading of the ship. I obtain this improved result by employing a course indicating pointer in addition to the ordinary compass card and by driving the compass card by the so-called ne or 36:1 or 180:1 repeater motor instead of the 1:1 motor, with,

however, proper reduction gearing therebetween.

The card, therefore, will actually'show a very small change of course, say one minute of arc, but such a small movement at the periphery of the compass card would not be noticeable by the helmsman, being on the order of only .001 inch. In order that the helmsman may detect the initial slight departure of the ship from the course and to give him immediate warning that the vessel has commenced to yaw in a new direction, I conneet the pointer referred to above to the card or motor through a. lost motion device in such a fashion that it will move through an initial angle of suilicient sizeto be readily noted by the helmsman. o My invention has especial' application toa repeater compass used in connection with an automatic steering gear for ships and, in fact, is shown in my prior application for letters Patent, Serial No. 16,173, nled April '13, 1935, for Automatic steering for ships. The present application is therefore a division of my aforesaid prior appremon- Referring to the drawings showing one form my invention may assume. Fig. 1 is a plan view of my improved form of steering repeater compass.

Fig. 2 is a diagrammatic view, partly in section, showing the elements of my invention.

Flgis awiringdiagmlnofthesame. lllg.4isadiagramshowlngtheinventionin provide a course indicating pointer 5 which may controller rings-in other words, in the followby means of a pinion. turnedY froma knob 32 PATENT OFFICE the forin it is shown in my aforesaid application.

As shown in Fig. 1, my improved steering repeater may have the appearance of an ordinary repeater compass with the usual 360 compass 5 card I, lubber line 2, casing 3, and setting knob 4 for setting the card. In addition, however, I

be set on any desired course by means of an auxiliary setting knob 6, so that it may always 'lo be kept on the lubber line 2. The compass card is controlled primarily from a repeater motor 1 which is preferably driven from a. multiple speed selsyn transmitter 8 on the gyro compass, this being usually driven at a 36:1 ratio. The 15 motor, however, is not gearedy directly to the card, but operates one portion of a two-part' follow-up controller 9. As shown, the motor I is directly connected to the trolley or revolving brush arm $9 of the controller. 20

Th'e controller is shown as provided with two split rings I5 and I6, half of each of which is dead and the live halves are connected respec tively to collector rings I1 and I8. The controller controls a power or servo motor I9 which is 25 shown as of the direct current type, having a shunt iield Winding 20 connected directly across the supply and a mid-tap resistance 2l connected across the armature, the center tap being connectedto one side of the line. It will readily be 30 seen that the motor will be driven in either direction, depending upon whether the trolleys are on the live section of ring I5 or ring I6, and that in the standstill position the motor is instantly brought to rest by dynamic braking. 35

Thepower motor is shown as geared directly,

through motor shaft pinion 22', reduction gears 22 and 80, gears 8l and 82 on shaft 2l, to the large gear 23 yon the shaft 83 of course pointer 5.

There is interposed between said motor and the 40 up connection between the motor and controller rings-a lost motion connection 25. Said connection is preferably adjustable so that the amount of lost motion, and thereby the amount 45 of initial throw of pointer 5, may be varied to suit the navigator. As shown, there is provided an eccentric cone 26 on the end of shaft 21, which partially enters a conical. depression 2B in a circular block 29 slidably but non-rotatably mount- 50 ed on shaft 3l. Said block may be raised and lowered to vary the amount of lost motion, as

and meshing with circular rack teeth 33 on the periphery of said block.

against the fixed abutmen 1 placelby collar 55.5

provided by a spring 40 between a collar 4l fixed on shaft 38, and a collar 42, slidably bi'it"-nin"btatbly mounted on the shaft 31-Hand -1normall pres d the differential rotates ge annular gear-45 secured to carries the contactor and.

troller 9, said sleeve beingJ-Y wn' as our al on the exterior of the cas'i'ngof'ft'lie'fmoto1'by' i gearednthrough' the" reduction gearing shown to thecard I'y instead of, or in addition to, driving a long bearing 10. Sleeve member 416,.,.is "shown, as having a pinion 41 thereon driving ai"'gear"48 o'nashait 4 8 w hichalsorcarriesra pinioni-Asfdriv'f ing a large gear 50, to the hub of which the come passfeardgl isvsecuredig j rl f1' ;;'I'he gear 48 is :preferably linotrigidlyl xed; zto the shaft '48,', howevermbuthas a slipfrictioncons nection therewith sogthat. the compass i card Smay be manually synchronized ,with the vmaster 'comipass. For this purpose, setting knob ;4, which `iis normally =.held 1in itsinoperative orgoutward aposi# tionfby-spring 5|-, 1 when pushed fin; ;bringsiy finto mesh the bevel gear 55 2,. on thep'shaft thereo f,: and bevel gear; ,5 3 on the shaft 48%, sogthata lby'turn'f ing the;lrnob,4 thea compass card 4may be ls'etrwithoutdisplacing the c ontrol1er.- The slip;- friction connection forjgear 48 isshownf as rprovided by a spring pressedclutch -face 54,1 slidably;` but; `nonrotatabiytsecured tothe r shaft 48,', -whichf presses against the face of the gearlllty 1whichis held in In Fig. 4, the partshavebeen numberedsimilarlyA to. Figa-2',Y with primed numbers, so `thatthe correspondingfparts will be readily' recognized, and whil ethearrangement; appears to be different,athe operation, is the same;r y Y In `this c,ase, the selsyn; repeater` ,1 is;sl 1 own` as gearedto the ,trolleygarniv `6910i Athe controller 9', andthe jpower motor I S is shown'Y-as-connected t0 the: shaft 30 of the differential 34f through gearing 5,65, sprocketsand chain ,drive 5 1'. In this lease; the. third ann of the 3 differential, 341 drivesthe course iliointerr.'L throughjhelical gear.- ing 58.7and-exible'shaft 5 9-f 1@ yTh 10st` motionf-.devie 12 vvmay ,be Similar .to that described v inconnection \with Fig; 2 and is shown as placed'betweens, es haftf andthe shaft -60 Vof-the gear l45, t which-is mounted the. controller. rines 15hand llisaid;t gear also driving the large gear.y 50: which rotates-thesleeve Gl carrying thepmpaSS-Qardr It@ In ythis case,l the variationfin the. amount-of lest-mauvais Shownl as :eieced: lfrom a Cam 52 Whihvraises and lowers a Shaft; @It :Whharrie :the hollow cone 28' 0n the lostlmotionrlevice the shaft 63 bring' lidably butA .non :rotatablv: mounted :within the heb O f; thegeer .bymeensfoi-forlt 61,;.y I'will reedilyfbeasfen-tha in oth forms Qi myinvientioeithe ourse pointer fors' f ;-wi11 be, gifverr' ari initie1 11lnovement Whenever-th ship Che-n gesiiis lir ti.r10f y ,eso as :te e1. he helmsmanfimmedia. warning @theta theffshipwis olstmgtionvcong Ween thel s power mowrsand its;controlleitfisovthat-fthemotoremust turn enough to take up this 1Q Str .motion fwheni it starts to turn in a different direction from that in which it has previously been turning, and this initial movement is transmitted to the course vpointer 5, but it is not transmitted to the compass card. The compass card therefore remains extremely accurate in itsz-indicatip '51j :anychanfes cul'dffbe naiewin he above construction and many apparently Widely differ- `t embodiments of this invention could be made ithout departing from the scope thereof, it is tende Hat-:al1 matter contained in the above ,in theaccompanying drawpreted as illustrative and not 20 lsaid card fromS-'the powerimotori4 185"- l""Ihiswill notiniianyfway alter the loperation'of :the pointer 5; :whiehwill continue-itc" give `m'agnified 'indica-v tions in case of change of the directionio'ff yaw 0fth'e'shp. 1.122 siti?, fw" 15' i if: Ai e `Havingr vdescribed my invention; what I f claim andLidesirefto secureby LettersfPatent `is: f in 'f .1'.fIn -liaj 'steering' repeater? compass, a .repeater Compass zoard, :"anfwauxiliary course" indicator mounted concentric 1; therewith; i `a compass f `re- -peater motor,:a reversingfcontrollerr actuated by saidmotor, 2a reversible@ power .motor 'governed by "saida controller Band rdriving said course indi# cator, a follow back drive from said power motor to'saidicontroller including a lost motion' device, andV means `for driving: said compassI card" also from".i .said` "follow: back ,driveVv and f lost motion devicepy l A `2.'1In'a Esteering repeater compass; a v.repeater compass card;V4 an' auxiliary courseindica'tor mounted for conjoint reading with said cardya compass repeater motor adapted to be 'rotated va multiple Ynumber .of v"times for` leach complete turn ofthe ship, a source'ofrpowerpal reversing controlleractuated :byxsaidfmotonwa reversible power motor.operated`lfromsaid controller and source of` power,l A driving said course indicator through reduction; gearing, a follow-back drive from" said powermotor to;,said -controller including a; lost motion: device; and `meansz for driving saidrcomJ- pass `card ,fromt said; follow. vbackv drive,V lost :motion v device {andy-reduction;gearing." z ;3.; In-i a: steering; `repeater compass, a repeater motor adaptedA to be rotated-.from :a 'master compass,l .a reversing controllergdirectly: connected to saidfmotor, affollow-uplparton said controller, a compass card driven'xthereby, a reversible motor governed by `said controller and driving-said, follow-up part, a course indicator also driven.by saidreversiblemotor and mounted'forfjoint reading with said ,card-and means'for.giving1said, indicatoran initial' extra movement not given the card `upon a1 change in,` the direction `of yawof heship; :f Ti? L7- f i 1,4. PA .steering-repeater compass for -ships :having twomov'able indicating elements,"one of which is a compass card and both of which normally -make onecomplte revolution zp'er fc'omplete turn of the ship, and means zien-imparting y,to f'onlyone of said/elementsfaniinitlal'magnifledathrow upon l l 2,120,951 ship. means for setting the other of said elements to show the ship's course, and means for imparting to said last namedY element anv initial magnied movement upon initial deviation .of the ship from its course.

` 6.`A steering repeater compass as claimed in claim 1, having manual means. for setting said course indicator to show any desired, course.

'7. In a steering repeater compass, a repeater motor normally rotated from a master compass, a compass card rotated in accordance with the movements of said motor, a reversing controller directly connected to said motor, a follow-up part on said controller, a reversible motor governed by said controller and driving said follow-up part, a course indicator also driven by said reversible motor, and means for giving said indicator an initial extra movement not 'given the card upon a change in the direction of yaw of the ship.

8. In a steering repeater compass, a repeater compass card, a concentric auxiliary course indicator, a compass repeater motor, a reversing controller actuated by said motor, a reversible power motor governed from said controller and driving said course indicator, and a follow back drive from said power motor to said controller including a lost motion device.

FREDERICK s. HODGMAN. 

